Taxanes are diterpene compounds which find utility in the pharmaceutical field. For example, taxol, a taxane having the structure: ##STR1## where Ph is phenyl, Ac is acetyl and Bz is benzoyl, has been found to be an effective anticancer agent.
Naturally occurring taxanes such as taxol may be found in plant materials, and have been isolated therefrom. Such taxanes may, however, be present in plant materials in relatively small amounts so that, in the case of taxol, for example, large numbers of the slow-growing yew trees forming a source for the compound may be required. The art has thus continued to search for synthetic, including semi-synthetic routes for the preparation of naturally occurring taxanes such as taxol, as well as for the preparation of analogues thereof.
Due to the complexity of the taxane ring structure, a taxane containing desired substituents on the ring system may more readily be prepared by the use of a starting material already having the basic taxane ring structure. Thus, for example, a compound having the taxane ring structure and containing a hydroxyl group at C-13 may be coupled with an intermediate compound to form a taxane having a desired sidechain at C-13, such as taxol.